Common software open source protocols

Preface

​ The open source agreement of third-party software used in software development is very important , Protect the rights and interests of programmers , Build an open source environment .

In this paper, the reference ：

• https://www.cnblogs.com/xiang–liu/p/11641471.html
• https://www.cnblogs.com/BangQ/archive/2011/07/19/2110886.html
• https://www.zhihu.com/question/41435612
• https://www.sohu.com/a/141652181_760387

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GPL （GNU General Public License）

​ Very strict open source agreement . As long as the code uses GPL Protocol code , It must be in GPL Protocol open source free , Cannot close source or charge . This is it. “ Infectious ”.Linux That is to say GPL Protocol open source .

characteristic ：

• Freedom of reproduction **： Allow software to be copied to anyone's computer , And there is no limit to the number of copies .**
• Freedom of communication **： Allow software to spread in various forms .**
• Charge propagation **： Allow the software to be sold on a variety of media , But you have to let the buyer know in advance that the software is available for free ; therefore , In general , Open source software makes money by providing users with paid services .**
• Freedom to modify **： Allow developers to add or remove software features , But after the software is modified, it must still be based on GPL License agreement authorization .

BSD（Berkeley Software Distribution）

​ High authority , Business friendly , Basically, you can completely control the code . But follow these three Conditions ：

• If the redistributed software contains source code , Then the source code must continue to follow BSD license agreement .
• If there are only binary programs in redistributed Software , You need to declare in the relevant documents or copyright files that the original code follows BSD agreement .
• The original software name is not allowed 、 Author's name or organization's name for marketing .

Apache （Apache License Version）

​ And BSD be similar ,Apache The agreement provides copyright and patent license for developers at the same time , Allow users the freedom to modify code and redistribute . However, the following requirements should be met 4 Conditions ：

• The software and its derivatives must continue to be used Apache license agreement .
• If the program source code is modified , It needs to be declared in the document .
• If the software is based on other people's source code , You need to keep the original code Protocol 、 trademark 、 Content information of patent declaration and other original author's declaration .
• If there is a declaration file in the redistributed Software , You need to mark Apache License agreement and other license agreements .

Those who use this protocol are ：Hadoop、Apache HTTP Server、MongoDB

MIT（Massachusetts Institute of Technology）

​ As long as the developer Keep the license information of the original author in the modified source code , Is one of the least restrictive agreements . Use MIT The software of the protocol includes PuTTY、X Window System、Ruby on Rails、Lua 5.0 onwards、Mono etc. .

GUN LGPL（GNU Lesser General Public License）

​ And GPL be similar ,LGPL Allow commercial software to reference through class libraries （link） The way to use LGPL Class library , and There is no need for open source commercial software code . But if you modify LGPL The code or derivative of the agreement , Then all the modified code , Both the extra code involved in the modification and the derived code must adopt LGPL agreement . therefore LGPL The open source code of the protocol is very suitable to be referenced by commercial software as a third-party class library , but Not suitable, hope to LGPL Protocol code based , Through the modification and derivative way to do the secondary development of commercial software to adopt .

WTFPL (Do What The Fuck You Want To Public License) A wonderful open source agreement

​ His official website ：http://www.wtfpl.net/ It's about you ** Do whatever you want . This should be the most relaxed agreement _,

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